The policies of defeated one-term presidents are not as easily reversed as their victorious successors, suffused with campaign rhetoric, sometimes suppose. That applies even when, as now, the winning party has majorities in both houses of Congress.

Those margins, after Democrats’ double wins in the Georgia Senate races Tuesday, are tenuous — 51-50 in the Senate (including Vice President Kamala Harris) and 222-211 in the House. They’re eerily similar to Republicans’ margins when George W. Bush became president 20 years ago: 51-50 in the Senate, 221-212 in the House.